The paper discusses the concept of traffic flow described by hyperbolic differential equations. In this paper the Lighthill-Whitham-Richards model (LWR model) is used to describe traffic flow. The ...said model uses two parameters to describe the traffic flow – density and average speed of vehicles. Numerical approximation of the LWR model is formulated through scalar conservation laws. The finite volume method is used for numerical results. The term of shock wave and propagation of rarefaction wave in traffic flow are described. This paper focuses on numerical simulation of traffic flow via fluid dynamics model for a single road with a traffic light. The results obtained in this paper are compared with previous studies.
U radu se razmatra pojam prometnog toka koji se opisuje pomoću hiperboličkih diferencijalnih jednadžbi. Model koji se koristi je Lighthill-Whitham-Richardsov model (LWR model). Navedeni model koristi dva parametra za opisivanje prometnog toka – gustoću i prosječnu brzinu vozila. Numerička aproksimacija LWR modela je formulirana preko zakona očuvanja. Također, kod numeričkih rezultata je korišten model konačnih volumena. Opisan je pojam udarnog vala i vala razrjeđenja u prometnom toku te prikazana simulacija prometnog toka koji na određenoj udaljenosti ima postavljen semafor. Dobiveni rezultati u radu su uspoređeni s rezultatima prethodnih istraživanja.
Unicameral bone cysts (UBC) are benign bone tumor-like lesions. Mostly they are located in the metaphyseal-diaphyseal region of long bones in children and adolescents. The etiology of UBC is still ...unclear. There is no consensus about the protocol of UBC treatment. The aim of this study was to evaluate the effectiveness of three different techniques for the treatment of UBC. This study included 129 pediatric patients with UBC treated at University Children's Hospital in Belgrade during the 8-year period. The mean follow up was 7.14 years. The following parameters were observed: gender, age, site, length of cyst, cyst index, cortical thickness, presentation of pathologic fracture, healing of cyst, treatment complications and length of hospitalization. These parameters were correlated to three treatment modalities, i.e. intracystic methylprednisolone acetate injection (group 1), curettage with bone grafting (group 2) and osteoinductive procedure using demineralized bone matrix (group 3). We found statistically significant differences in healing of the cysts and length of hospital treatment between groups 1 and 2, and between groups 2 and 3. In conclusion, complete healing of UBC can be achieved only using open surgery procedure. Intracystic methylprednisolone acetate instillation can be considered a good option for initial treatment of UBC.
Abstract Background Closed reduction and percutaneous pinning are the preferred treatment of displaced supracondylar humeral fractures in children. The purpose of this study is to evaluate the ...non-standard Dorgan’s method and compare its results with those of the standard percutaneous cross pinning method in treatment of unstable or irreducible Gartland type II and III supracondylar humeral fractures in children. Patients and methods This was a prospective evaluation of 138 consecutive patients with Gartland type II or III extension supracondylar humeral fractures referred to University Children’s Hospital during a four-year period. The patients were randomized into two groups: the first group, comprised of 71 patients, was treated with standard pin configuration and the second group, comprised of 67 patients, underwent Dorgan’s method. The study included 88 boys and 50 girls aged 1.5–11.4 years (mean 6.5 ± 2). At initial presentation 8.7% (n-12) fractures were classified as Gartland type IIa, 25.4% (n-35) as Gartland type IIb and 65.9% (n-91) as Gartland type III. Results Flynn’s criteria were used to evaluate the results. An excellent clinical outcome was reported in about 90% of patients (n-90) treated with standard pin configuration and 89.5% (n-60) of patients treated with Dorgan’s method. There were no statistically significant differences in outcomes between the groups in terms of their gender, age, fracture types, function and cosmetics. Neurological lesions were observed in 9.9% of patients (n = 7) who were treated using the standard configuration Kirschner pins, while in those treated by Dorgan’s method neurological complications were not observed. However, the procedure time was longer (mean 36.54 ± 5.65 min) and radiation exposure significantly higher (mean 10.19 ± 2.70 exposures) in the group that was treated using Dorgan’s method, compared to the conventional method (mean 28.66 ± 3.76 min and 7.54 ± 1.63 exposures). Conclusion Two laterally inserted crossed pins provide adequate stability with good functional and cosmetic outcome for most unstable paediatric supracondylar humeral fractures with no risk of iatrogenic ulnar nerve injury.
Cilj ovog rada je prikazati rezultate analize opće okoline hrvatske cementne industrije primjenom PEST/LE modela. Metodološki pristup temeljen je na prikupljanju i obradi relevantnih sekundarnih ...podataka te su provedena primarna istraživanja u kojima je korištena metoda polu-strukturiranog intervjua. Prema rezultatima istraživanja, ispitanici su evidentirali ukupno dvanaest čimbenika opće okoline relevantnih za cementnu industriju u Hrvatskoj. Od toga je pet čimbenika označeno kao strateška prijetnja: ekološki zahtjevi, domaća gospodarska situacija, demografska kretanja, ekološka svijest građana i poduzeća i zakonska regulativa u području poreza. Preostalih sedam čimbenika označeno je kao strateška prilika: raspoloživi prirodni resursi, međunarodna gospodarska situacija, brzina tehnoloških promjena, zakonska regulativa u području izdavanja građevinskih dozvola, politička stabilnost, državne investicije u infrastrukturu i državna politika gospodarenja otpadom. Prema rezultatima istraživanja, prilike u općoj okolini djeluju jače nego prijetnje tj. opća okolina u cjelini pozitivno djeluje na cementnu industriju u Hrvatskoj.
The paper presents the results of an analysis of the cement industry in Croatia by using the Porter's model of five competitive forces. The methodological approach is based on collecting and ...processing relevant secondary data and on conducting primary research by using the survey method. Based on the results of quantitative research, the intensity of competitive forces in the cement industry in Croatia is rated weak to moderate which makes the industry averagely attractive. This is the result of the bargaining power of buyers which is rated medium to strong, of the intensity of rivalry among existing companies which is rated medium, of the bargaining power of suppliers which is rated medium, of the low-rated threat of substitute products or services and of the low-rated risk of potential entrants. The analysis of secondary data confirms such results. Based on the results of the analysis, important strategic initiatives are identified for improving the industrial structure and competitive position of companies in the Croatian cement industry: continuity of high quality products, cost efficiency, investing in new technology, partnerships with customers and suppliers, strengthening logistic activities and own distribution channels, and cooperating with government bodies.
Unicameral bone cysts (UBC) are benign bone tumor-like lesions. Mostly they are located in the metaphyseal-diaphyseal region of long bones in children and adolescents. The etiology of UBC is still ...unclear. There is no consensus about the protocol of UBC treatment. The aim of this study was to evaluate the effectiveness of three different techniques for the treatment of UBC. This study included 129 pediatric patients with UBC treated at University Children's Hospital in Belgrade during the 8-year period. The mean follow up was 7.14 years. The following parameters were observed: gender, age, site, length of cyst, cyst index, cortical thickness, presentation of pathologic fracture, healing of cyst, treatment complications and length of hospitalization. These parameters were correlated to three treatment modalities, i.e. intracystic methylprednisolone acetate injection (group 1), curettage with bone grafting (group 2) and osteoinductive procedure using demineralized bone matrix (group 3). We found statistically significant differences in healing of the cysts and length of hospital treatment between groups 1 and 2, and between groups 2 and 3. In conclusion, complete healing of UBC can be achieved only using open surgery procedure. Intracystic methylprednisolone acetate instillation can be considered a good option for initial treatment of UBC. Key words: Bone cysts; Child; Injections, intralesional; Bone transplantation; Bone matrix Solitarne kostane ciste (SKC) su dobrocudne kostane lezije slicne tumorima. Najcesce su lokalizirane u metafizno-dijafiznoj regiji dugih kostiju djece i adolescenata. Etiologija SKC nije razjasnjena. Ne postoji konsenzus o protokolu lijecenja SKC. Cilj studije bio je procijeniti ucinkovitost tri razlicite tehnike lijecenja SKC. Studija je obuhvatila 129 bolesnika lijecenih u Sveucilisnoj djecjoj bolnici u Beogradu tijekom 8 godina (2007.-2014.). Srednje razdoblje pracenja bilo je 7,14 (2,5-10) godina. Parametri za ukljucivanje bili su: spol, dob, lokacija ciste, velicina ciste, indeks ciste, debljina korteksa, patoloska fraktura, cijeljenje ciste, komplikacije lijecenja i trajanje hospitalizacije. Usporedili smo navedene parametre s tri razlicite tehnike lijecenja: apliciranje metilprednisolon acetata (MPA) unutar ciste (skupina 1), kiretaza i umetanje kostanog presatka (skupina 2) i osteoinduktivni postupak upotrebom demineralizirane kostane medustanicne tvari (DKM) (skupina 3). Utvrdena je statisticki znacajna razlika u cijeljenju cista i trajanju hospitalizacije izmedu skupina 1 i 2 te izmedu skupina 2 i 3. U zakljucku, potpuno lijecenje SKC moze se jedino postici otvorenom kirurskom tehnikom i time sprijeciti moguci rizik od zaostalih lezija i fraktura. Minimalno invazivna metoda aplikacijom MPA unutar ciste moze se smatrati dobrom opcijom za pocetno lijecenje SKC dugih kostiju. Kljucne rijeci: Kostane ciste; Dijete; Injekcije, intralezijske; Kostana transplantacija; Kostani matriks
Purpose: The purpose of the study was to determine whether lateral soft-tissue release (LSTR) has a beneficial or detrimental effect on the outcome of distal Chevron first metatarsal osteotomy (DCMO) ...in the treatment of moderate hallux valgus (HV). Methods: We compared the effect of different surgical treatments in 2 groups of patients: group I (23 patients, 25 feet, average age of 55 from 43 to 77 years) was subjected to DCMO only, whereas group II (18 patients, 23 feet, average age of 59 from 52 to 70 years) was subjected to DCMO with LSTR. The American Orthopaedic Foot and Ankle Society’s Hallux Metatarsophalangeal-Interphalangeal scale survey was conducted postoperatively, followed by the brief survey on postoperative patient satisfaction. The patient follow-up period was from 18 to 24 months after surgical treatment, on average. Results: After surgical intervention, both groups of patients presented with an improved HV angle, but there was no significant difference between the groups. However, group II showed significant improvements in medial sesamoid bone position and patient satisfaction scores as compared with group I. Conclusion: Our midterm follow-up of surgical treatments for moderate HV deformity suggests that both procedures provide good postoperative results. However, according to our results, DCMO with LSTR provides better results than procedures without LSTR.
Levels of Evidence: Therapeutic, Level III: Retrospective comparative study
This paper presents financial ratio analysis of the cement industry and its comparison to non-metal mineral product (NMP) industry and the Croatian economy. Activity, productivity, profitability and ...debt ratios are analyzed for 2013 and liquidity and performance ratios are analyzed for the period from 2009 - 2013. Profitability and productivity ratios show higher values in the cement industry as compared to the Croatian economy and NMP industry. Total asset turnover ratio is lower in the cement industry than that of the Croatian economy and NMP industry while other activity ratios show higher values. Debt level of cement industry is lower compared to the Croatian economy average but maturity structure of funding sources is inadequate. In the period from 2009 to 2012 liquidity of the cement industry was higher than the liquidity of the Croatian economy as a whole and in the period between 2010 and 2011 it was also higher than that of NPM industry. Performance ratios in cement industry are low.
U radu su analizirani financijski pokazatelji cementne industrije u Hrvatskoj, uz usporedbu u odnosu na industriju ostalih nemetalnih mineralnih proizvoda (NMP) te gospodarstvo Hrvatske u cjelini. ...Financijski pokazatelji proizvodnosti, aktivnosti, zaduženosti i profitabilnosti analizirani su za 2013. godinu, dok su pokazatelji likvidnosti i ekonomičnosti analizirani za razdoblje od 2009. do 2013. godine. Prema pokazateljima proizvodnosti i profitabilnosti, cementna je industrija u boljem položaju u odnosu na gospodarstvo Hrvatske i industriju ostalih NMP-a. Koeficijenti obrtaja ukupne imovine cementne industrije niži su u odnosu na industriju ostalih NMP-a i gospodarstvo Hrvatske, dok drugi pokazatelji aktivnosti pokazuju bolje vrijednosti. Zaduženost cementne industrije niža je u odnosu na prosjek gospodarstva Hrvatske, ali je struktura ročnosti izvora financiranja neadekvatna. Likvidnost je cementne industrije u razdoblju od 2009. do 2012. godine veća nego likvidnost ukupnog gospodarstva, a od 2010. do 2011. godine i veća od prosjeka industrije ostalih NMP-a. Ekonomičnost je cementne industrije niska.
U radu su prikazani rezultati analize cementne industrije u Hrvatskoj provedene prema Porterovu modelu pet konkurentskih sila. Metodološki pristup temeljen je na prikupljanju i obradi relevantnih ...sekundarnih podataka te na provedenom primarnom istraživanju u kojemu je korištena metoda anketiranja. Prema rezultatima kvantitativnog primarnog istraživanja, intenzitet konkurentskih sila u cementnoj industriji u Hrvatskoj je slab do srednji, što tu industriju čini srednje privlačnom. To je posljedica srednje do jake pregovaračke moći kupaca, intenziteta suparništva među postojećim konkurentima koji je ocijenjen srednjim, pregovaračke moći dobavljača koja je ocijenjena srednjom te nisko ocijenjene prijetnje od zamjenskih proizvoda i niske ocijenjene prijetnje od ulaska
novih konkurenata. Analiza sekundarnih podataka potvrđuje takve nalaze. Na temelju rezultata analize industrijske strukture u cementnoj industriji u Hrvatskoj, prepoznat je niz strateških inicijativa za poboljšanje atraktivnosti cementne industrije i položaja poduzeća
u toj industriji: osiguravanje kontinuiteta visoke kvalitete proizvoda, poboljšanje troškovne učinkovitosti, investiranje u novu tehnologiju, razvijanje partnerskih odnosa s kupcima i dobavljačima, jačanje logistike i vlastitih kanala distribucije te suradnja s državnim tijelima.
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